Gerrit Rietveld's Aluminium Chair is one example of the designer's attempts to make a chair out of one piece of material. Rietveld initially designed chairs that could be formed from one sheet of plywood in 1927 and in 1930 he began experimenting with sheet metal. This particular example is dated 1942. As apparent from his notes, this example was merely a prototype of a final design to be executed in folded fibreboard. Rietveld modified this aluminium version by folding the edges of the chair in order to increase the material's stability. The perforations add further strength to the chair, as opposed to having merely a decorative purpose, as seen in some versions of the Zig-Zag Chair. The Aluminium Chair was never mass produced; only five examples were created.